Re: [RFC 2/2] initramfs with digital signature protection
From: Dmitry Kasatkin
Date: Thu Apr 11 2013 - 04:08:18 EST
(in plain text)
I respond to the original question of this thread.
signed initramfs allows not only to add keys to the keyrings but
perform other initialization,
which requires user-space.
Keys can be embedded into the kernel. This is fine.
On Thu, Apr 11, 2013 at 12:05 AM, Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 2013-04-10 at 15:42 -0400, Vivek Goyal wrote:
>> On Tue, Apr 09, 2013 at 11:07:10PM -0400, Mimi Zohar wrote:
>> > The module keyring is a special case. Loading these keys from the
>> > kernel and, presumably, locking the keyring is probably fine. In the
>> > case of IMA, however, files will be signed by any number of package
>> > owners. If the _ima keyring is locked by the kernel, how would you add
>> > these other keys?
>> Who are package owners here. IOW, in typical IMA setup, where are the keys
>> and when are these keys loaded in ima keyring?
> Suppose I install third party packages not signed by the distro, but by
> the package owner (eg. google, rpmfusion, ...). Not only does the
> package signature need to be verified on installation, but the files
> need to be installed with signatures. For IMA to enforce file
> integrity, the package owner's public key needs to be added to the _ima
>> If we trust root and keys can be loaded any time later, then signed
>> initramfs will not solve the problem either.
> Locking the keyring in the kernel will limit the set of permitted keys
> to only those specified in UEFI db or builtin. Locking the keyring in
> the "early" initramfs, will allow the system owner, whose key is in the
> UEFI db, to specify additional keys, such as those for third party
> packages. Not all public keys belong in the UEFI db.
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